1. Field of the Invention
The present invention relates to an integration rod for a projector, and more particularly, to an integration rod with a strengthened structure.
2. Description of the Related Art
An integration rod is an important optical element for a projector, and is usually a hollow rod with an inner reflective surface that reflects light many times to provide even illumination. The typical hollow integration rod utilizes a lens plated with a metal film to provide light reflection capabilities. However, the metal film can deform under high temperatures.
The typical hollow integration rod utilizes glue to fix a plurality of lenses into a predetermined shape (such as a hollow rectangular rod, or a hollow hexagonal rod). As a result, the characteristics of the glue may determine the structural strength and heat resistance capabilities of the hollow integration rod.
The typical glue has a working temperature range of about 100˜150° C. When the internal working temperature rises, the strength of this glue decreases dramatically. The glue looses its ability to hold together the structure of the hollow integration rod, which can lead to the collapse of the hollow integration rod.
Since projectors are becoming increasingly popular, in order to provide clear and bright images, the typical projector utilizes a high power illumination device as a projector light source. As the light intensity of the projector increases, the working temperature may rise from 150° C. to 250° C., or even to 300° C. Under these high temperatures, the glue in the integration rod starts to get brittle, accelerating the potential for collapse of the integration rod.
In the industry, there are ceramic adhesives that are capable of enduring temperatures in excess of 1000° C. without suffering degradation. However, when this ceramic adhesive is used for long periods in high humidity environments, or in humid alkaline conditions, the glue may begin to hydrolyze, which reduces the adhesive capabilities of the glue, accelerating the collapse of the integration rod.
Therefore, it is desirable to provide an integration rod for use in a projector that mitigates and/or obviates the aforementioned problems.